package com.xingzhe.pengji.security.interceptor;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.security.access.SecurityMetadataSource;
import org.springframework.security.access.intercept.AbstractSecurityInterceptor;
import org.springframework.security.access.intercept.InterceptorStatusToken;
import org.springframework.security.web.FilterInvocation;
import org.springframework.security.web.access.intercept.FilterInvocationSecurityMetadataSource;

public class MyFilterSecurityInterceptor extends AbstractSecurityInterceptor implements Filter {
	//与applicationContext-security.xml里的myFilter的属性securityMetadataSource对应，  
	//其他的两个组件，已经在AbstractSecurityInterceptor定义  

	@Autowired
	private FilterInvocationSecurityMetadataSource securityMetadataSource;

	@Override
	public SecurityMetadataSource obtainSecurityMetadataSource() {
		return this.securityMetadataSource;
	}
	
	public FilterInvocationSecurityMetadataSource getSecurityMetadataSource() {
		return this.securityMetadataSource;
	}

	@Override
	public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException,
			ServletException {
		FilterInvocation filterInvocation = new FilterInvocation(request, response, chain);
		invoke(filterInvocation);
	}

	public void invoke(FilterInvocation filterInvocation) throws IOException, ServletException {
		// object为FilterInvocation对象  
		//super.beforeInvocation(filterInvocation);源码  
		//1.获取请求资源的权限  
		//执行Collection<ConfigAttribute> attributes = SecurityMetadataSource.getAttributes(object);  
		//2.是否拥有权限  
		//this.accessDecisionManager.decide(authenticated, object, attributes);  

		InterceptorStatusToken token = super.beforeInvocation(filterInvocation);
		try {
			filterInvocation.getChain().doFilter(filterInvocation.getRequest(), filterInvocation.getResponse());
		} finally {
			super.afterInvocation(token, null);
		}
	}

	@Override
	public Class<? extends Object> getSecureObjectClass() {
		//下面的MyAccessDecisionManager的supports方面必须放回true,否则会提醒类型错误  
		return FilterInvocation.class;
	}

	public void setSecurityMetadataSource(FilterInvocationSecurityMetadataSource securityMetadataSource) {
		this.securityMetadataSource = securityMetadataSource;
	}
	
	@Override
	public void destroy() {

	}

	@Override
	public void init(FilterConfig filterConfig) throws ServletException {

	}
}
